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Brian S

Farmall 806 no TA lube pressure

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Howdy Folks,

 

New user and first time poster here, long time googler and have found great info off this forum to help me out on other projects. I've read a lot of MCV/no lube posts on here and other sites, talked with several people, and have been left scratching my head. Any pointers, information, and advice would greatly be appreciated.

 

This is kind of a long winded story so bear with me, I want to try to be as thorough as possible.

 

We've had trouble on and off the last season or two with the TA in the old man's 806. I talked with a local wrench turner, he suggested going thru the MCV and installing a new pump. It got the works, gaskets, seals, orings, and a spring kit from Hy Capacity. I had a little trouble getting it to work so I had him take a look at it and it was said that it was good (he's a Hy Capacity dealer and was in the middle of a 806 TA at the time so I feel confident that the MCV was good). It didn't completely fix all our issues but we were trying to limp the old girl thru the spring until we had more time to tear it down. We've had a hunch that the TA was going, it was just a matter of time. Well it finally did while I had it hooked to the chisel plow. That was in April. 

 

Fast forward to Christmas 2019, my brother and I had time off work so we tore into it. I ordered a new HD TA kit from Hy Capacity thru our local Case IH dealer. Everything came apart fine, everything seemed to go back together fine. Got the tractor all bolted back together, made all the connections, got everything ready to fire it up. Note also that the tractor received a new wiring harness as the old one had 50 years of rigging in it, and that the oil tell light wasn't operational when the TA quit. All that is in good working order now.

 

Once we got it fired up, warmed up, topped off all the fluids again, I started into doing pressure checks since the tell light wouldn't shut off. I had not moved the tractor more than a few feet forwards or backwards in the shop, more of a check to make sure everything functioned after being reassembled. First time around, I had good clutch pressure, the guage I'm using is in too high of graduations to give an exact figure (I have a 600psi gauge on order and should be here in a day or two) but reads closer to the 300psi mark than the 200 in both direct drive and on the TA side. I did not have lube pressure in either position, but if I hold the lever in between, it would hold 20psi. I called the local dealer, talked with one of their guys, I also talked to a gentleman at Hy Capacity. He recommeded installing the dowel pin that come with the kit in place of the steering check valve. Did that, clutch pressures remained the same, lube pressure came up to 20 psi on both sides. I then ordered and installed a new spring and check valve, the old one did show some wear. The new check valve didn't help at all, still had good clutch pressure with 0 lube pressure. I then called out to Hy Capacity again, spoke with the same gentleman, obviously he couldn't recommend running the tractor with that dowel pin in, I had read its possible to do, he confirmed that its possible to do, though highly discouraged from Hy Capacity. Talked with my local guy again, we concluded that running that dowel pin was the way to go, not knowing where exactly where the leak is coming from, but hoping the blockage would be enough to compensate for the leakages (keep in mind the old girl has 8500 hours on the clock).

 

So off came the MCV again, dowel was installed, all the connections were made again with the hope that would cure our issue. Fired the tractor up, still good clutch pressures, seemed to have 20 psi for a bit while the oil was cold. As the tractor warmed up, it started to loose pressure slowly. If you crank the wheels to lock, it drops straight to 0. If i press the brakes, the pressure drops. Makes no difference whether its in DD or TA. Pressure still comes back if i hold the TA lever in the middle position. I read on one forum or another to try blocking the oil line that feeds the brakes. tried that while it was still warm, lube pressure sits around 16 psi, but in time the pressure drifts off to 0. 

 

Obviously I have some kind of internal leak. I've ruled out the brakes, which leaves the steering, the TA itself, or the MCV to be the culprit, unless I'm missing something. I haven't disassembled the MCV, it only had a few hours on it before the old TA failed. The steering sucked on that tractor all my life (I'm 27 for what its worth), but you could crank the wheel around with one finger after installing the new pump and going thru the MCV. I have not touched anything steering related yet. One thing to note as well, my local guy asked if I had lube pressure when I went thru the MCV in the spring, I dont remember checking for it, we may not have had it then since the light didn't work and that was the cause of death of the old TA.  

 

I'm hoping one of you wise gentlemen have some thought, things to look at, things to check, general insight that might point me in the right direction. 

Thanks, Brian

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300 is a nice low and high side pressure if you only have lube in between you got issues inside something is leaking I’ve been there done that most likely time for another ta. Ups dropped it or what not broke seal 

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There is three tubes that go through TA housing into the TA the top one I believe is lube by chance you didn't forget or cut an oring.

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Welcome to the forum 😊 After the MCV over haul and new springs in it you should have 300 psi and that is just fine and remember have 300 psi over 250 psi you ta will last longer . I would check your jumper tube orings like the other guy is telling you just to make sure you didn't cut one . If you could get an engine oil ( pre lube unit ) put Hy Tran in it and use your rubber tip blow gun on the end of the hose and set you pre luber to 20 psi , put it up to the (lube ) jumper tube and see if your leaking in the TA unit . You can check the hi and low side clutch packs with your pre luber and the clutches will lock up and you can look up in the ta housing to see if your jumper tube orings are leaking .Dont ever blow in there with full air psi from your compressor or you will blow the lube baffle out . 

You can cap off the brake valve and the power steering circuits to make sure there not returning oil to sump . This stuff is getting old and stuff leaks by causing these types of problems . Don't be afraid to try a total different MCV valve , in the last few years I have had two different ones that would not hold the same psi between the hi and low sides . Took all the new parts out of my valve that I just went through and put them in another used valve and worked perfect . 

Good luck , and if you can't get it send me a PM and I can send you the testing stuff out of the IH service manual .

Danny 

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Just currious ...... if when you installed the new TA unit was the hose clamp loose on the input shaft that holds the TA bearing carrior causing the the carrier to slide up on the shaft when the TA unit was lowered into the housing ? 

This can allow the lube baffle in the housing to come out of place resulting in a Lube leak .

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The seat for the check valve can be replaced. I've only done one and I see on the parts website it's no longer available. Would need to take one out of another housing I guess. 

 

#5 in the picture

https://partstore.caseih.com/us/TownCountryImpl1/parts-search.html#epc::mr53293ar1239221

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Thanks for the responses guys. 
 

TW7110- I did install new orings on the oil tubes when it was going back together, doesn’t mean i didn’t tear one during the installation though. They were lubed with Hy Tran for what it’s worth.
 

DirtBoyz -We do have another 806 and swapping MCVs has crossed my mind but I hate to have both of Them down in the shop at the same time. The other is more of a chore tractor for us.

The supply for the brakes is currently capped. I’ll have to dig around and see what I can find to plug the steering circuits. 

I’ll have to see what I can come up with for a pre luber too. Never used one, I’ll have to ask some folks I know if they have one.

 

FarmallFixer- Hose clamp being loose on during the installation- that’s totally possible and I didn’t catch it. Keep in mind this is my first trip to the rodeo on a TA job. Is there a way I can check the lube baffle and is it repairable if I did mess it up?

 

FarmerFixEmUp- The seat you speak of I assume is the counterbore that’s check valve sits into. I didn’t even realize that was a removable piece so I learned something there.

 

I’ll see what I get into tonight and this weekend with the old girl. Hopefully we can get it narrowed down a bit more.

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Brian S  - When hook up a preluber as another member suggested to the lube should rule out the lube baffle as the culprit if it will hold around the 20 psi of pressure . One way you can attach the preluber is to tap the inside of lube tube to 1/8 pipe thread so an fitting can be screwed into it for the preluber .  The tube is still fine to use after tapping , it will just have threads inside of it .

The lube baffle is a very thin copper disk approximately 3 inches in diameter with a tang on it the sits into a notch in the housing . There are 2 very light springs that hold it against the input shaft bearing to seal the oil . 

Another has mentioned to not to use full air pressure in the jumper tube for suppling lube when checking TA clutch operation after assembly of trans , this is why it blow out or warp the brass lube baffle , and pressure should be limited to around 20 psi .

Kuddos to you for doing your first TA job , there are alot of fine very knowledgeable experienced  members on this forum who are more than willing to help ..... just keep asking questions .

By the way a long time ago in a land far far away when I was doing one of my first TA's I got well informed about " Mister Lube Baffle " through the " School of Hard Knocks and Life Lessons " I made the mistake once and never forgot my lesson . LOL !!

Is it repairable -- Yes , not sure if CIH has them available yet not , havent tried to get one in maybe 3 decades but I am sure they can be aquired someplace , the aftermarket rebuilders get them from somewhere . I use Hy Cap TA's bet your dealer could maybe get one from them .

The bad part is if in fact it is the problem the TA would have to be removed for repair so do the simpler things first .

Bob

 

 

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After reading more of your thread , if I am understanding right , when you have the MCV spool in the middle position your pressure is OK ? Correct ? That does lead me to think the problem is interna in TA due to spool in the mid position cuts oil supply off to the TA .

The MCV supplies to all the rest of the drivetrain too includeing the rearend , if the pressure is OK in mid position the other the rearend lube system must not be the culprit causing the low lube pressure .

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1 hour ago, FARMALL FIXER said:

After reading more of your thread , if I am understanding right , when you have the MCV spool in the middle position your pressure is OK ? Correct ? That does lead me to think the problem is interna in TA due to spool in the mid position cuts oil supply off to the TA .

The MCV supplies to all the rest of the drivetrain too includeing the rearend , if the pressure is OK in mid position the other the rearend lube system must not be the culprit causing the low lube pressure .

That is correct. I think I have located a pre luber from a buddy of mine. 
 

I haven’t located caps for the steering circuits (I assume by that it’s the lines coming out of the valve that sits between the starter and the battery, correct?). I’ll get some from the parts store in the morning. 

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16 hours ago, FARMALL FIXER said:

After reading more of your thread , if I am understanding right , when you have the MCV spool in the middle position your pressure is OK ? Correct ? That does lead me to think the problem is interna in TA due to spool in the mid position cuts oil supply off to the TA ..

That is what I was thinking............

  

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I had a internal leak on a torque job maybe 30 years ago, found top jumper tube went too deep into the rebuilt torque housing and oring on outside end of jumper tube was on the inside of the tran. housing causing leak, i could see it with a mirror, ended up  putting a lock washer in the port in the torque to keep jumper tube from going in as far. Steve

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You can pull mcv back off a little and insert a shim to block the two tubes feeding direct drive and ta  to find out if your losing the oil internally. Or put a plug in each jumper that won't move into tube.  Not lube jumper though.    Another thing, in the middle position, the normal regulated pressure should drop 20 psi.  If it drops much more and is doing it on both direct and TA that also indicates leak internal in TA unit, like sealing ring on shaft or damage to TA when assembling clutch housing to engine. 

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Think someone on here told me to cut a piece of soda can to block the tubes, hold it on with some grease until the mcv is bolted on, that works pretty slick.

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I have used a large headed rivet close to the internal diameter of the tube too and it worked good .

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Ok guys,

So I got all the lines expect the ones to and from the oil cooler capped off this morning. Just fired it back up and let it run at 1500 rpm for a half hour or so. Clutch pressures look great on the new gauge. Hangs around 290 on both DD and TA. Drops to 230-240 if I hold the ta lever in the middle. Cold lube pressure showed 18 psi on both DD and TA. After the half hour of running, clutch pressures remained pretty even still. Lube pressure slowly dropped until we got to 0. I shut it down at that point. 
 

I’m going to drain the oil next and the jumper tubes just to inspect the orings. I though I might try that can idea, plenty of them around to try it quick. Which of the tubes is the lube tube? Top one is what I think I seen somewhere.
 

Judging my your responses, it’s not looking promising. 


Again, thanks guys, I’m learning a lot about this old girl during this project. You have been a big help.

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That's not the right port to check pressure for ta.  

Bottom plug of MCV is the one

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9 minutes ago, ole 815 said:

That's not the right port to check pressure for ta.  

Bottom plug of MCV is the one

The one with the pressure relief valve stuck up in it then?

AA908A02-F9DF-473A-8603-85DF89A1D49A.jpeg

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Yep, I use a fitting with jic nipple, or you need a plug that has been drilled and tapped, jus depends what you got for gauge fittings.

That is the steering relief valve. That stays up in there when checking.  Fitting holds it in.

 

Have never used that other port,  so maybe it works, but jus dont know,   its regulated pressure but not sure if it gives you the same results when you are diagnosing with putting lever in middle position etc....

Maybe pete23 will chime in, he is way more knowledgeable on MCV  than me.

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Noted, I was misinformed there. Learning more as I go. Much appreciated 

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Use bottom port where steering relief valve is.  You are reading steering back pressure in other port and not regulated pressure.  I was wondering why you had such a huge drop when in middle position.  

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Ok good news and bad news. Good news is I found enough fitting to get me plumbed in to the correct port so I’ll reverify my pressures again. 
 

The bad news, I pulled the jumper tubes. Bottom two seemed fine. The top one I played **** with to get out. The oring that seats into the TA is a little tore up, not sure if it’s from installation or pulling it back out. I should have another one around here and I’ll stick it back together. 69CF3044-BE37-49B3-A953-A10628FC1580.thumb.jpeg.8a9bb8aedfc64ca14c793440965a1008.jpeg

28748021-7326-4D9E-AAE1-98122C167895.jpeg

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Put the inner o-ring on after you slide tube thru transmission case, or at least that is the way I do them. 

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1 minute ago, CIHTECH said:

Put the inner o-ring on after you slide tube thru transmission case, or at least that is the way I do them. 

Good advice. 

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Good Evening Gentlemen,

 

I got some time to wrench this evening. I tapped out the jumper tubes and hooked up a pre luber to them. Top jumper I assume is the lube tube I assume, with 20 psi applied, Hy Tran ran out the quill end of the TA. Orings on all the jumpers seemed to be sealing well. I didn’t notice anything major on the bottom two jumper tubes, just some oil seeping outside the trans housing from not having the fittings snug enough to the tubes. 
 

That being said, I’m assuming bad news with this particular TA. Thoughts?

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4E036609-8120-4254-966D-D10A4EFCF437.jpeg

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